dc.contributor.author | COEY, JOHN MICHAEL DAVID | |
dc.date.accessioned | 2009-08-14T09:20:09Z | |
dc.date.available | 2009-08-14T09:20:09Z | |
dc.date.issued | 2000 | |
dc.date.submitted | 2000 | en |
dc.identifier.citation | S.M. Watts, S. Wirth, S. von Molnar, A. Barry and J.M.D. Coey 'Evidence for two-band magnetotransport in half-metallic chromium dioxide' in Physical Review B, 61, (14), 2000, pp 9621 - 9628 | en |
dc.identifier.other | Y | en |
dc.identifier.other | Y | |
dc.description | PUBLISHED | en |
dc.description.abstract | Magnetotransport measurements were made on patterned, (110) oriented CrO2 thin films grown by the high-pressure, thermal decomposition of CrO3 onto rutile substrates. The low-temperature Hall effect exhibits a sign reversal from positive to negative as the magnetic field is increased above 1 T, which may be interpreted within a simple two-band model as indicating the presence of highly mobile (?h=0.25 m2/V s) holes as well as a much larger number of less mobile electrons (n=0.4 electrons/Cr). Between 50 and 100 K, the field at which the sign reversal occurs rapidly increases and a contribution from the anomalous Hall effect becomes significant, while the large, positive transverse magnetoresistance (MR) observed at low temperatures changes over to a predominantly negative MR. These changes correlate with a thermally activated dependence in the resistivity of the form T2e-?/T with ?~80 K, reflecting the lack of temperature dependence in the resistivity at low temperatures and a T2 behavior above 100 K. The high mobilities at low temperature which result in the observed positive MR reflect the suppression of spin-flip scattering expected for a half-metallic system. However, the changes in magnetotransport above the temperature ? must be due to the onset of spin-flip scattering, even though kB? is much less than the expected energy gap in the minority spin density of states. The significance of ? is discussed in terms of recent models for another half-metallic system, the perovskite manganites, and the possible formation of ``shadow bands.'' | en |
dc.description.sponsorship | This research was sponsored by DARPA through the Office
of Naval Research, ONR Grant Nos. N00014-96-1-0767
and N00014-99-1-1094. S.W. acknowledges support by the
Humboldt Foundation, Germany. | en |
dc.format.extent | 9621 | en |
dc.format.extent | 9628 | en |
dc.format.extent | 120077 bytes | |
dc.format.mimetype | application/pdf | |
dc.language.iso | en | en |
dc.publisher | American Physical Society | en |
dc.relation.ispartofseries | Physical Review B | en |
dc.relation.ispartofseries | 61 | en |
dc.relation.ispartofseries | 14 | en |
dc.rights | Y | en |
dc.subject | Physics | en |
dc.title | Evidence for two-band magnetotransport in half-metallic chromium dioxide | en |
dc.type.supercollection | scholarly_publications | en |
dc.type.supercollection | refereed_publications | en |
dc.identifier.peoplefinderurl | http://people.tcd.ie/jcoey | |
dc.identifier.rssinternalid | 3882 | |
dc.identifier.uri | http://hdl.handle.net/2262/31768 | |